How Accurate Is Synastry in Astrology?

When it comes to love, friendship, and even business partnerships, astrology offers more than just your daily horoscope. One of the most fascinating tools it provides is synastry—the art of comparing two birth charts to understand how people connect, clash, and grow together.

Whether you're a total beginner or you’ve been diving into birth charts for a while, synastry can reveal patterns in your relationships that are hard to ignore. So how accurate is it, really? Let’s break it down.

What Is Synastry in Astrology?

Synastry is the astrological technique used to compare the birth charts of two individuals. While your own birth chart reflects your personal traits and tendencies, synastry overlays one chart onto another to see how the planetary placements interact. Think of it like cosmic chemistry—it highlights attraction, compatibility, tension, and even areas of growth.

For example:

• When one person’s Venus (love) aligns with another’s Mars (desire), the chemistry can be intense and magnetic.

• If someone’s Moon (emotions) connects with your Mercury (communication), they might feel like someone who truly gets you.

• Hard aspects, like squares or oppositions, can create friction but also opportunities for deeper understanding if both people are willing to grow.

How Does a Synastry Chart Work?

A synastry chart is created by overlaying one person's natal chart onto another's to analyze planetary interactions. You will need your birth times to make this overlay as accurate as possible.

Here are some key steps I like to use when looking into someone’s synastry chart:

1. Compare the Sun, Moon, and Rising signs – the Big 3 that shape personality and core needs.

2. Evaluate Venus and Mars – the planets of love, desire, and attraction.

3. Look at Saturn – for long-term potential and emotional challenges.

4. Check the Houses – where one person's planets fall in another’s chart (the 5th for romance, 7th for partnership, 8th for intimacy).

5. Assess aspects – harmonious (trines, sextiles) or challenging (squares, oppositions) angles between planets.

How Accurate Is It?

In my experience, synastry is surprisingly accurate when it comes to explaining the unspoken parts of relationships. It can validate what you feel, highlight recurring patterns, and even shed light on the emotional dynamic between you and someone else.

It’s not about predicting whether a relationship will succeed or fail. Instead, it offers insight into how and why you interact the way you do. For example, maybe your partner feels emotionally distant, and you find out their Saturn sits on your Moon. That can feel cold, but it can also point to lessons around emotional maturity and commitment.

The catch? Synastry is most powerful when you already understand your own chart. If you don’t know how you operate emotionally, it’s harder to interpret how someone else fits into your world.

What Makes It Work?

When interpreted with care, synastry can reveal patterns that feel deeply familiar or even supernatural. To get the most out of it, here are a few key guidelines to keep in mind:

Synastry works best when:

• Both charts are read with an open mind and some context.

• You consider both easy and challenging aspects. Be willing to see the challenging aspects as an opportunity for growth rather than an obstacle in the relationship.

• You look beyond Sun signs and consider planets like the Moon, Venus, Mars, and Saturn.

• You avoid jumping to conclusions based on one or two placements.

Synastry can show you who feels familiar, who activates certain parts of you, and who challenges you to grow. But no chart guarantees a perfect match or a guaranteed breakup. Real relationships still depend on communication, timing, and personal growth.

Synastry vs. Composite Charts

I think it’s worth mentioning that there are additional tools to evaluate a relationship in Astrology. While synastry compares two individual birth charts to explore how one person influences the other, a composite chart combines both charts into a single, averaged chart that represents the relationship as its own entity. Think of synastry as showing the back-and-forth dynamic between two people, while the composite chart reveals the identity, themes, and overall tone of the relationship itself.

You might use synastry when you want to understand emotional triggers, attraction, or communication patterns between two people. On the other hand, a composite chart is helpful when you're looking at the purpose or direction of the relationship. For example, a couple with strong synastry might feel deeply connected, but if their composite chart has tension around emotional expression or stability, they may struggle to make the connection last long-term.

Astrologers may use both charts together to get the full picture of a relationship's chemistry and its long-term potential. While there are many websites that allow you to generate both synastry and composite charts for free, the interpretations for composite charts in particular are usually limited or overly simplified. That's because composite charts require a deeper understanding of midpoint theory and house placement patterns, which can be more complex to interpret. If you're seriously exploring your relationship through astrology, I highly recommend taking time to understand your Synastry first and then working with a knowledgeable astrologer to unpack the composite chart. They can help you understand the purpose, emotional tone, and evolving path of the relationship in a way that goes beyond surface-level analysis.

Final Thoughts

So how accurate is synastry? When used thoughtfully, it can be a powerful tool for reflection and connection. It won’t fix your love life, but it will help you understand the deeper patterns playing out underneath the surface. And sometimes, that clarity is exactly what you need to navigate relationships with more confidence.

Curious to see what your synastry says about your connections? Stay tuned for more compatibility breakdowns and relationship insights on the blog or contact me here for more information. 

Tips for Deeper Learning:

• For a visual, explore an example of a synastry chart to see how the planetary placements interact.

• Use tools like Astro.com, Astro-seek.com, or Cafe Astrology to generate free synastry charts.

• When reading aspects, focus on how planets like Venus, Mars, the Moon, and Saturn relate between charts.

  
  

If you have any questions, drop them in the comments!

FAQs About Synastry

What does synastry mean in astrology? 

Synastry is a method of comparing two birth charts to understand compatibility, attraction, and relationship dynamics.

Can synastry tell if we are soulmates? 

Synastry can reveal strong emotional and energetic connections, but soulmate potential also depends on growth, communication, and shared values. In some cases I have even seen a karmic connection between two people. However, I like to emphasize that again this is an opportunity for growth not a sign that this individual is the right one for them. 

How do I get a synastry chart? 

You can use free tools online by entering both birth details, or consult an astrologer for a professional reading. I do offer Synastry readings along with relationship coaching services. I can also refer you to an Astrologer that specializes in other areas as well. 

Which placements are most important in synastry? 

In my opinion, Sun, Moon, Venus, Mars, and Rising sign connections are often key, as well as Saturn for long-term growth and commitment.

What’s the difference between synastry and composite charts? 

Synastry compares how you affect each other. Composite charts show the energy of the relationship as a whole.